how to stop mooring chain corrosion

[Romany 162]

Does anybody know if I could stop my galvanised mooring chain from corroding by fitting an anode to it - say at slightly above the point where the chain sinks to seafloor at lowest tide? 

[waikiore 399]

Galv chain should not be permanently immersed you should have black chain down there, galv only at the surface bit if you dont have a strop.

[SanFran 12]

You're talking 2 different things....  Rust, ie oxidation, and galvanic corrosion.  An anode will only stop the later 

[Frank 157]

Back in the day when my local club also serviced the members moorings we tried bolting blocks of zinc to the upper chain which was black steel with only the light buoy chain being galvanised the observed results on my mooring were

1. The zinc block did not seem to dissolve much.

2. It did not increase the life of the chain.

3. The prop shaft anode dissolved in 3 months instead of lasting a year.

4. The propellor surface became pitted.

Another vessel suffered corrosion and pitting on the surface of the steel bilge keels and other members reported their protective anodes were dissolving faster.

We abandoned the practice after two seasons.